路由状态收集

功能描述

使用场景

Dubbo 的许多流量管理功能都是基于 Router 实现的。在生产环境中，如果流量结果不符合预期，可以使用路由状态命令检查路由状态以定位可能存在的问题。

如何使用

查看路由缓存状态

当 Dubbo 接收到地址变更时，会将地址信息推送到所有 Routers，这些 Routers 在此阶段可以预先计算路由包并进行缓存，避免调用分组参数时需要遍历所有提供者进行计算。Dubbo 3 中引入的 StateRouter 提供了通过 qos 命令工具实时获取每个路由状态的能力。

运维人员可以通过 getRouterSnapshot 命令获取路由状态。有关具体命令，请参考 getRouterSnapshot 命令文档。

**注意：此功能仅支持 StateRoute，并且 StateRouter 需要基于 AbstractStateRouter 实现 doBuildSnapshot 接口。**

查看实际请求的路由计算结果

在 Dubbo 3 中默认情况下，当路由过滤器为空时，会打印路由计算的节点状态。运维人员可以通过日志判断每个路由的计算结果是否符合预期。

日志格式

No provider available after route for the service service from registry registration center address on the consumer consumer IP using the dubbo version 3.0.7. Router snapshot is below:
[ Parent (Input: Number of input addresses of the current node) (Current Node Output: Number of calculation results of the current node) (Chain Node Output: Number of intersection results of the current node and subsequent nodes) ] Input: Examples of input addresses (up to 5 are displayed) -> Chain Node Output: Example of addresses output by the current node (up to 5 are displayed)
  [Route name (Input: number of input addresses of the current node) (Current Node Output: number of calculation results of the current node) (Chain Node Output: number of intersection results of the current node and subsequent nodes) Router message: routing log] Current Node Output: current node Example of addresses output (up to 5 displayed)
    [routing name (Input: current node input address number) (Current Node Output: current node calculation result number) (Chain Node Output: current node and subsequent node intersection result number) Router message: routing log] Current Node Output: current input Examples of addresses for (show up to 5)

注意

路由日志需要依赖路由实现来判断 needToPrintMessage 参数，并在需要时写入 messageHolder 路由日志
由于多级路由的结果是结果的交集，因此当前节点的计算结果在与后续级别的交集后可能为空

日志示例

[19/07/22 07:42:46:046 CST] main WARN cluster.RouterChain: [DUBBO] No provider available after route for the service org.apache.dubbo.samples.governance.api.DemoService from registry 30.227.64.173 on the consumer 30.227.64.173 using the dubbo version 3.0.7. Router snapshot is below:
[ Parent (Input: 2) (Current Node Output: 2) (Chain Node Output: 0) ] Input: 30.227.64.173:20881,30.227.64.173:20880 -> Chain Node Output: Empty
  [ MockInvokersSelector (Input: 2) (Current Node Output: 2) (Chain Node Output: 0) Router message: invocation.need.mock not set. Return normal Invokers. ] Current Node Output: 30.227.64.173:20881,30.223.64.17 :20880
    [ StandardMeshRuleRouter (Input: 2) (Current Node Output: 2) (Chain Node Output: 0) Router message: MeshRuleCache has not been built. Skip route. ] Current Node Output: 30.227.64.173:20881,30.227.624.1803:
      [ TagStateRouter (Input: 2) (Current Node Output: 0) (Chain Node Output: 0) Router message: FAILOVER: return all Providers without any tags ] Current Node Output: Empty, dubbo version: 3.0.7, current host: 30.227 .64.173

开启路由全采样

在一些特殊情况下，请求可能会调用到错误的服务器，但由于地址选择不为空，无法看到路由的处理信息。此时，您可以 [通过 qos 开启全路由采样](../../. ./reference-manual/qos/router-snapshot/)。可以通过 qos 的 getRecentRouterSnapshot 命令远程获取最新的路由快照。

dubbo>getRecentRouterSnapshot
1658224330156 - Router snapshot service com.dubbo.dubbointegration.BackendService from registry 172.18.111.184 on the consumer 172.18.111.184 using the dubbo version 3.0.9 is below:
[ Parent (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) ] Input: 172.18.111.187:20880,172.18.111.183:20880 -> Chain Node Output: 172.18.111.187:20880.3172.18 :20880
  [ MockInvokersSelector (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) Router message: invocation.need.mock not set. Return normal Invokers. ] Current Node Output: 172.18.111.187:20880,172.183.111. :20880
    [ StandardMeshRuleRouter (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) Router message: MeshRuleCache has not been built. Skip route. ] Current Node Output: 172.18.111.187:20880,172.1803:1121.88
      [ TagStateRouter (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) Router message: Disable Tag Router. Reason: tagRouterRule is invalid or disabled ] Current Node Output: 172.18.111.187:20880,172.183.111. 20880
        [ ServiceStateRouter (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) Router message: Directly return. Reason: Invokers from previous router is empty or conditionRouters is empty. ] Current Node Output: 172.18.111.187:20880 ,172.18.111.183:20880
          [ AppStateRouter (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) Router message: Directly return. Reason: Invokers from previous router is empty or conditionRouters is empty. ] Current Node Output: 172.18.111.187:20880 ,172.18.111.183:20880

1658224330156 - Router snapshot service com.dubbo.dubbointegration.BackendService from registry 172.18.111.184 on the consumer 172.18.111.184 using the dubbo version 3.0.9 is below:
[ Parent (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) ] Input: 172.18.111.187:20880,172.18.111.183:20880 -> Chain Node Output: 172.18.111.187:20880.3172.18 :20880
  [ MockInvokersSelector (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) Router message: invocation.need.mock not set. Return normal Invokers. ] Current Node Output: 172.18.111.187:20880,172.183.111. :20880
    [ StandardMeshRuleRouter (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) Router message: MeshRuleCache has not been built. Skip route. ] Current Node Output: 172.18.111.187:20880,172.1803:1121.88
      [ TagStateRouter (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) Router message: Disable Tag Router. Reason: tagRouterRule is invalid or disabled ] Current Node Output: 172.18.111.187:20880,172.183.111. 20880
        [ ServiceStateRouter (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) Router message: Directly return. Reason: Invokers from previous router is empty or conditionRouters is empty. ] Current Node Output: 172.18.111.187:20880 ,172.18.111.183:20880
          [ AppStateRouter (Input: 2) (Current Node Output: 2) (Chain Node Output: 2) Router message: Directly return. Reason: Invokers from previous router is empty or conditionRouters is empty. ] Current Node Output: 172.18.111.187:20880 ,172.18.111.183:20880

···

dubbo>

注意

如果由于日志框架不匹配导致日志为空，可以参考日志框架适配和运行时管理动态修改日志输出框架。

上次修改时间：2023 年 1 月 2 日：Enhance en docs (#1798) (95a9f4f6c1c)